1. Field of Invention
The present invention relates to a vacuum pump for a vehicle which is mounted to a vehicle so as to generate vacuum pressure; and, particularly, to a vacuum pump of a vehicle for reducing operation noise capable of reducing pressure pulsation in a section within which pressure varies rapidly during operation of the vacuum pump, resulting in a reduction of operation noise.
2. Description of Related Art
A vehicle is provided with a vacuum pump to generate vacuum pressure for driving a variety of devices operated by the vacuum pressure. For example, in a vehicle equipped with a diesel engine, vacuum pressure is required to operate devices such as a braking system to operate a brake, an EGR valve, a throttle body, and a VGT. In addition, also in a vehicle equipped with a gasoline engine, a vacuum pump is provided in order to maintain vacuum pressure at a certain level or less such that proper vacuum pressure is stably applied to a variety of devices.
However, in a conventional vacuum pump for a vehicle, there are problems in that noise occurs according to operation of the vacuum pump. That is, the vacuum pump includes a rotor rotating in a space defined by a housing and a vane which is eccentrically rotated within the housing by the rotor, and generates vacuum pressure in such a way to compress air within the space and discharge the compressed air to the outside while the vane rotates in an eccentric state.
In this case, lubricant to smoothly operate the vacuum pump for a vehicle is supplied into and discharged from the vacuum pump. During discharge of the lubricant, noise occurs according to operation of the vacuum pump for a vehicle.
Such noise does not greatly affect driving performance of the vehicle, but acts as a factor of degrading comfortableness because the noise is transferred to a driver and a passenger. In addition, since devices using vacuum pressure are increasing in the vehicle and thus operating time of the vacuum pump for a vehicle is increased, an unpleasant feeling is increased due to operation of the vacuum pump.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.